Study On Preparation Of Oxide Dispersion Strengthened Cooper Alloy And Application In Diamond Tools

Solid solution strengthening is generally used to optimize the matrix with addition of alloy elements in diamond tools’manufacture. Cobalt based matrix has the optimum comprehensive properties but cobalt is expensive. So there is necessary to develop the matrix with low cobalt content or without cobalt. Copper based matrix is widely used in the manufacture of diamond saw blade for its excellent formability and low sintering temperature. But there will produce much heat when diamond blades work which make matrix softening at high temperature. And it will deteriorate the holding force and shorten the service life. So it is a entry point to improve the service life of copper based diamond blade by enhance the resistance of softening at high temperature. Oxide dispersion strengthening (ODS) can strengthen the matrix and improve the resistance of softening at high temperature as well. Thus we take the oxide dispersion strengthened brass as research object in this essay combining with the R&D condition of GRIPM. Research tasks are as follows:(1) Take the alumina dispersion strengthened copper powder and zinc powder as raw material and make the dispersion strengthened brass with zinc weight proportion of 20% by diffusion at 500℃ for 1h. The apparent density and oxygen content of prepared ODSCuZn20 alloy powder are 2.52g/cm3 and 3457ppm.(2) Study the hot-press properties of ODSCuZn20 alloy powder with the contrast of ordinary CuZn20 powder. The result shows the dispersed alumina phase in ODSCuZn20 sintered samples have good strengthening effect. The hardness of ODSCuZn20 sintered sample is increased by11HRB compared with ordinary CuZn20 sintered sample and the TRS of ODSCuZn20 sintered sample is 517MPa when sintered at 760℃ for 3min with pressure of 30MPa.(3) For exploring the resistance of softening at high temperature of ODSCuZn20 sintered sample, we keep the sintered samples for 1h at the temperature of 600℃、700℃、 800℃. Then quench with water and test the hardness of sintered samples. The hardness of ODSCuZn20 sintered sample almost keeps constant while the hardness of ordinary CuZn20 sintered sample decreases sharply, which indicates ODSCuZn20 have better resistance of softening at high temperature.(4) For studying the practical applied effect of ODSCuZn20 alloy powder, we use ODSCuZn20 and ordinary CuZn20 alloy powders to instead the CuSn10 alloy powder in typical diamond tools matrix. Then make diamond saw blades and take cutting experiment. The cutting results shows the blade with ODSCuZn20 has similar cutting speed with the two other kinds of blades. And the service life of blade with ODSCuZn20 is prolonged by 68% and 96.8% respectively comparing with blade with ordinary CuZn20 and CuSn10. Then observing the blades surface morphology with SEM, which shows the furrows of ODSCuZn20 blade matrix is shallower with more obvious "tadpole" tailing indicating that the matrix has better support to diamond particles. The statistical result of different wear form of diamonds shows the matrix with ODSCuZn20 has lower dropout rate which is favor of prolonging the service life.